5 6 Mr. Smithson on the Composition of the 
hydrogene ; or of carbonate of lime, if only that it was a com- 
pound of lime, carbon or diamond, and oxygene. In fact, 
totally dissimilar substances may have the same ultimate ele- 
ments, and even probably in precisely the same proportions ; 
nitrate of ammonia, and hydrate of ammonia, or crystals of 
caustic volatile alkali,* both ultimately consist of oxygene, 
hydrogene, and azote. 
It is not probable that the present ore is a direct quadruple 
combination of the three metals and sulphur, that these, in 
their simple states, are its immediate component parts ; it is 
much more credible that it is a combination of the three sul- 
phurets of these metals. 
On this presumption I have made experiments to determine 
the respective proportions of these sulphurets in it. 
I have found 10 grains of galena, or sulphuret of lead, to 
produce 12.5 grains of sulphate of lead. Hence the 60.1 
grains of sulphate lead, which Mr. Hatchett obtained, cor- 
respond to 48.08 grains of sulphuret of lead. 
I have found 10 grains of sulphuret of antimony to afford 
11,0 grains of precipitate from muriatic acid by water. Hence 
31.5 grains of this precipitate are equal to 28.64 grains of sul- 
phuret of antimony. 
The want of sulphuret of copper has prevented my deter- 
mining the relation between it and black oxide of copper, but 
this omission is, it is evident, immaterial, as the quantity of this 
sulphuret in the ore must be the complement of the sum of 
the two others. 
But as the iron is a foreign adventitious substance in this 
ore, it follows that the foregoing quantities are the products 
* Fourcroy, Syst. des Con. Cbcm. t. I. p. 88. 
